Like countless films before it and countless more to come, 2010's How to Train Your Dragon centered around a misunderstood outcast. Two, in fact - Hiccup, the nerdy son of a viking chief, and the dragon, Toothless, that he rescues and befriends. But rarely do coming-of-age films get to expand beyond that premise with their characters. More often than not - particularly with animated movies of this kind - a sequel is more than likely to repeat the patterns of the first, reiterating the coming-of-age journey with only incremental progress.

But that's a pitfall writer/director Dean DeBlois intelligently avoids in How to Train Your Dragon 2, allowing his characters to grow and his story to expand into new territory. While the previous film was largely about finding one's place, the sequel is about finding one's family - wherever that family may be, and in whatever form. And with all the emotional baggage and conflict that comes with it.

For Hiccup, family was always something of a difficult concept. His father, Stoick (Gerard Butler), raised him mostly by himself, but never quite managed to understand his meek, very un-Viking-warrior-ish son. And it wasn't until Hiccup discovered Toothless (after failing to do his village proud by killing it) that he found his place - and a pet, in the process. And a best friend.

But just as it seems the film has made his life, at last, a contented one, fate throws his understanding of his family into an entirely new light when he stumbles upon his long-lost mother, Valka (Cate Blanchett), who he's never known and who his father has mourned for years.

This is a potentially melodramatic concept, but DeBlois doesn't treat it that way; in fact, he uses it to explore some surprisingly nuanced dynamics among the suddenly expanded Haddock family. The combination of joy and betrayal - both on his face and in his body language - is palpable for Hiccup. He doesn't know how he should feel, really - but it's confusion most of all. Valka, meanwhile, had her reasons for departing when Hiccup was just an infant, but that does nothing to curtail the anguish we see on her face as recognition of her once-abandoned son sets in.

She knows that, no matter how good a reason she had for leaving all those years ago, it doesn't take away the pain, nor does it make this moment of reunion any easier. As it turns out, her world and Stoick's were in irreconcilable conflict. His was a culture built on fighting and killing dragons, while she wanted to protect them. And so she's spent the last two decades doing just that. At the very least, she and Hiccup immediately have something in common. After all, it's his kinship with Toothless that brought dragons and Vikings together, and they've been living in harmony for the last five years.

But all is not peaceful in this world, which is where Valka's unexpected reappearance sets in. Despite the ongoing peace between dragons and humans in Hiccup's village, many in the outside world still treat dragons as the enemy - notably Drago (Djimon Hounsou), a bloodthirsty dragon hunter, and those who do the hunting for him like Eret (Kit Harrington). Valka has been rescuing and protecting dragons from the likes of Drago for years.

Meanwhile, Drago's increasing power has brought out the warmonger in Stoick, Gobber and the rest of Berk, setting the stage for a battle laced with personal histories and resentments.

One of the most impressive things about Dragon 2 is its refusal to treat the aspects of the story as simple problems to be solved while distracting its audience with pretty visuals, which tends to be the case with a lot of animated fare (particularly sequels). DeBlois takes the characters' precarious emotional circumstances seriously, and presents questions of forgiveness, tolerance and loyalty with the complexity they deserve. That he was even allowed to go into somewhat darker territory is a testament to his commitment to expanding this world and these characters, rather than repeating the journeys they've already had.

Of course, it doesn't hurt that the movie also delivers in many of the same ways that made the first movie so popular, namely its joy and adventurousness (particularly during the in-flight sequences with Hiccup and Toothless) and sly, character-specific (rather than joke- or pop culture-based) comedic asides. Roger Deakins returns as the visual consultant, and I was even more impressed this time around with the sophistication of the way he and DeBlois shoot the action. Consider the way the camera swoops in and around characters mid-battle, heightening the sense of danger and fun while never losing any sense of geography.

In a lot of ways, How to Train Your Dragon 2 plays like a classic swashbuckling adventure, its action playing out at sea as often as in the sky. Its overall approach reminded me in some ways of Darren Aronofsky's Noah. I don't mean in any literal fashion, but as I wrote before, that movie was about difficult faith, and it presented its family dynamic accordingly - difficult, challenging, even upsetting. This movie does the same. It is not some trite old story about a kid who learns a lesson and plays the hero, or about a father or mother who conveniently comes to understand the right thing at the right time. It is messy and sad and joyful, sometimes all at once. Even the boy-and-his-pet angle - which was covered as extensively as possible in the first entry - finds new depths and insights this time around. While not all of the film's story diversions work as well as those of its predecessor, it remains a worthy follow-up in large part because it refuses to do the same thing over again.